North Atlantic Right Whale

Like other right whales, the North Atlantic right whale, also known as the northern right whale or black right whale, is readily distinguished from other cetaceans by the absence of a dorsal fin on its broad back, short, paddle-like pectoral flippers and a long arching mouth that begins above the eye. Its coloration is dark grey to black, with some individuals occasionally having white patches on their stomachs or throats. Other unique features include a large head, which makes up a quarter of its total body length, narrow tail stock in comparison to its wide fluke, and v-shaped blowhole which produces a heart-shaped blow. The most distinguishing feature for right whales is their callosities: rough, white patches of keratinized skin found on their heads. The right whale's callosities provide habitat for large colonies of cyamids or whale lice, which feed on the right whale's skin as these small crustaceans cannot survive in open water. The relationship between cyamids and right whales is symbiotic in nature but is poorly understood by scientists. Callosities are not caused by the external environment and are present on fetuses before birth. …

It is not known how many populations of North Atlantic right whales existed prior to whaling, but the majority of studies usually consider that there were historically two populations, one each in the eastern and western North Atlantic. There are however two other hypotheses which claim, respectively, one super-population among the entire North Atlantic (with mixing of eastern and western migratory routes occurring at locations in relatively high latitudes such as in the Denmark Strait), and three sub-populations of eastern, western, and central Atlantic right whales (with the central stock ranging from Greenland's Cape Farewell in summer to the Azores, Bermuda, and Bahamas in winter, although recent study indicates that the Azores had probably been a migratory corridor rather than a wintering ground). Recent studies revealed that modern counterparts of the eastern and western populations are genetically much closer to each other than previously thought. Right whales' habitat can be affected dramatically by climate changes along with Bowhead whales.

Western population. In spring, summer and autumn, the western North Atlantic population feeds in a range stretching from Massachusetts to Newfoundland. Particularly popular feeding areas are the Bay of Fundy, the Gulf of Maine and Cape Cod Bay. In winter, they head south towards Georgia and Florida to give birth. …

North Atlantic right whales are promiscuous breeders. They first give birth at age nine or ten after a year-long gestation; the interval between births seems to have increased since the 1990s, and now averages three to six years. Calves are 13–15 feet (4.0–4.6 m) long at birth and weigh approximately 3,000 pounds (1,400 kg). The North Atlantic right whale's penis can reach at least 1.8 m (5 ft 11 in) in length.